Submitted to: Aquaculture America Conference
Publication Type: Abstract Only
Publication Acceptance Date: August 5, 2009
Publication Date: N/A
Technical Abstract: The high temperature and pressure achieved during cooking extrusion has been shown to affect nutrient availability. To determine the effects of extrusion temperature on the efficacy of mannanoligosaccharide (Bio-Mos) in channel catfish, 2 commercial and 4 experimental diets were fed for 9 wks and then challenged with Edwardsiella ictaluri. Catfish (10.3 ± 0.3 g) were randomly assigned to six treatments: Com-None (36% crude protein commercial catfish diet, sinking); Com-Bio (commercial catfish diet with Bio-Mos® supplemented at 4 g/kg, sinking); Low-None (low temperature process without additive, floating); High-None (high temperature process without additive, floating); Low-Bio (low temperature process with 4 g/kg diet Bio-Mos®, floating); High-Bio (high temperature process with 4 g/kg diet Bio-Mos®, floating). SGR was higher and FCR was lower for the fish fed floating diets compared to sinking diets (P < 0.01). Survival after E. ictaluri challenge was higher (P < 0.01) for the fish fed Com-Bio compared to fish fed Com-None (60.0 +/- 5.3% vs 40.0 +/- 6.4%) and for fish fed Low-Bio compared to Low-None (70.0 +/- 4.2% vs 45.0 +/- 5.4%). Increasing processing temperature of diets containing Bio-Mos®; however, resulted in a decrease in survival. Extruding catfish diets supplemented with Bio-Mos at lower temperatures may provide another strategy to control ESC in catfish. Potential mechanisms of action of Bio-Mos® on immune function will also be discussed.